Forced-draft furnace



June 10, 1924.

L. E. SMITH ET AL FORCED DRAFT FURNACE Filed Aug. 14, 1922 3 Sheets-Sheet 2 I nae/123719 LEZJmd/i, (.Zulw

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L. E. SMITH ET AL FORCED DRAFT FURNACE Filed Aug. 14 1922 3 Sheets-Sheet fi 5 56.5.

Patented June 10, 1924.

UNITED STATES PATENT oFF cs.

LAUNCELOT EUSTACE SMITH, O'F SOUTH SHIELDS, GORNELIS ZULVER, OF LONDON, AND HERBERT ALEXANDER THOMPSON, OF NORTH SHIELDS, ENGLAND.

FORCED-DRAFT FURNACE.

Application filed August 14, 1922. Serial No. 581,817.

To all whom 2'2. may concern:

Be it known that we, LAoNoELo'r EUs'rAoE SMiTH, Smiths Dock Company, Limited, High Docks, South Shields, in the county of Durham, England, a subject of the King of Great Britain, CoRNELIs ZULVER, of St. Helens Court, Great St. Helens, in the city of London, England, a subject of the Queen of the Netherlands, and HERBERT ALEX- ANDER THOMPSON, of 9 Cleveland Terrace, North Shields, in the county of Northumberland, England, a subject of the King of Great Britain, have invented a new and useful Improvement in or Relating to Forced- Draft Furnaces, of which the following is a the specification.

This invention has for its object to provide an improved construction of forced draft furnace capable of use with either solid or liquid fuel as desired, the improved construction being of the type wherein the oil burner is arranged in the same fire opening as is used for coal or solid fuel when the furnace is converted for its use.

A forced draft furnace front made in accordance with this invention, and adapted for conversion to oil or solid fuel firing as desired comprises the combination of an ordinary forced draft furnace front having the front end of its fire opening closed by a cover plate or casing, an oil burner extending through the fire opening and mounted on the front cover plate, or casing, a deflecting or bafiiing cone mounted around the inner end of the oil burner between the fire opening and the furnace, a closing plate adapted to close the ash pit and in some cases extending around the fire door so as to support the said deflecting cone or baiiie air supply valves, and means for deflecting the air in its passage from the said valves to the fire opening around the burner.

The furnace front which carries the fire opening may in some cases be extended in the front by an external casing adapted to cover the fire opening, and more or less of the ash pit opening and to provide an air passage to the front end of the fire opening from the side valves or dampers of the furnace front.

In amodified construction the oil burner is mounted on the usual fire door or a substituted closing plate on thefront of the fire opening and the air is admitted to the said fire opening by holes in the base thereof, leading from an enclosed ash pit chamber to which air is admitted by the side valves, and in some cases, in addition to the air holes in the base of the fire opening, air may be admitted by side opening in the fire opening from the surrounding saddle chamber and inlet valves thereto, and in addition if required, air may be admitted to said fire opening by side openings therein fitted with weighted dampers.

The invention may be adapted to a furnace front of the type fitted for coal firing through the fire opening and side firing by oil burners located at the sides of the fire opening, the central firing oil burners being fitted according to the present invention as above and as hereinafter set forth to the fire opening, the air supply being arranged far from the side valves and the ash pit chamber or from saddle valves, or both.

In a further modification the furnace front carrying the fire opening is spaced stead of the front thereof, and with such.

an arrangement an additional air supply may be arranged for by way of side openings in the fire opening from the saddle plate and from damper covered apertures below the ,same.

Helical vanes may be fitted around the oil burners in suitable position.

The baffling cone may be fitted to the end of the fire opening by lugs instead of being mounted upon the closing plate.

In the accompanying drawings we have illustrated various constructions carried out in accordance with the present invention.

Fig. 1 isa front elevation of a Howden or similar type of coal burning forced draft front having our invention applied thereto.

FigaQ is a sectional elevation of- Fig. '1.

Fig. 3 is a similar view to Fig. 2 showing a similar construction modified by the inclusion of vanes.

Fig. 4 is a face view showing a Fig. 3.

detail of r Fig. 5 shows another modification in vertical section.

Fig. 6' is a vertical section of a construction similar to Fig. 5, but fitted with helical Figs. 7 and 8 are sectional details showinghelical vanes of different form to those shown in Fig. 14.

In the construction shown in Figs. 1 and 2 an ordinary Howden or similar type of coal burning forced draft furnace front a has fitted thereon an external casing a adapted to cover the fire opening 5 and the ash pit opening 0'. This casing a is provided with suitable lugs so that the ash pit door (1 may be'fitted to the casing a, to give access to the ash pit instead of providing a complete ly new door; The ordinary saddle Valve 6 may be allowed to remain for use in coal firing when required, and the side valves f are employed for oil firing.

As shown in Fig. 2 the burner holder 9 which carries the burner g is mounted on the external casing a' and attached to the inside of the said casing and surrounding the burner g is a flame tube and flared end 9 The usual dead plate for carrying the coal burning fire bars is removed and a closing plate 2' suitably protected by a lining of refractory materials" is fitted on the 7 inside of thefurnace front a so as to close the front end of the furnace except for the fire opening I). A cone or deflecting battle it is attached to the closing plate 2' so as tosurround the oil burner g which passes 7 through the fire opening I). The closing plate 6 is provided to prevent any air passing into the furnace, as would happen in the ordinary way through the ash pit opening 0.

In operation, for oil burning the air after passing through the usual side valves f is compelled to pass up through the external casing a, as shown by the arrows and into and through the fire opening 6 round the burner g" and thence through the cone h to the furnace, this arrangement ensures that all the air supply is taken round the burner g and can only pass through to the furnace by the cone h, thereby ensuring a more perfeet combustion.

Figs. 3 and f'show an arrangement similar 1 to that sho wn in Figs. 1 and 2 but modified by the provision of helical vanes j of any desired number or angle arranged so as to surround the burner 9 1n order that a rotati'v'e motion may be imparted to the air to eflec't a more complete mixing of the same with the oil.

The external casing a may be secured to the ordinary coal burning front a in any suitable manner such as lugs and bolts, studs, flanged plates and so forth, and this external v casinga may be of any desired shape or size. If desired an additional door (not shown) may be fitted on the top half of the said casing a to give access to the fire opening in a similar manner to the ordinary lire door.

Fig. 5 shows a further modification wherein the front a carrying the fire opening I) is spaced outwardly by means of a flange a? so as to bring the closing plate i and cone l1- relatively further inwards from the back of the front plate a and this closing plate 1' is retained in position and at the right distance apart by means of bolts 2 and ferrules or distance pieces 2.

By this arrangement an air space (I is left between the plate 11 and the back of the furnace front a and the air supply to the oil burner g and cone h and furnace passes in at the back of the fire opening 1), instead of through the same, the said air passing from the side valves or dampers (see Figures 1 and 2) as shown by the arrows, up through the space 9 and from thence around the oil burner and into the furnace through the cone it.

In this construction the closing plate i may be extended as shown to the full diameter of the furnace thereby providing a large air heating space in order to ensure that all the air entering the furnace is thoroughly heated before coming into contact with the oil spray from the burner.

The cone h and closing plate 2' are suitably protected by fire brick or refractory lining i as before, and as shown a door 1' may be fitted in the closing plate 2' and the lining i in order to give access, when necessary to the furnace through the ash pit.

Fig. 6 shows a similar construction to that illustrated in Fig. 5 but in this case ad litional air inlet openings at and 21. have been provided in the side of the fire opening I) and if required, openings such as 1' may also be arranged for.

Helical vanes such as j may also be provided at the entrance to the cone l1 as de' scribed with reference to Figs. 3 and 4.

Figs. 1' and 8 show constructions similar to Figs. 5 and 14. having alternative forms of helical vanes j fitted around the oil burner and inside the cone it.

What we claim as our invention, and desire to secure by Letters Patent is 1. The improved forced draft furnace front adapted for conversion to oil or coal firing comprising a casing covering the furnace front and having an air heating chamber, said casing projecting from one wall of said furnace front and terminating on at least one side short of the other wall so as to leave a passage between its end and the said other wall of said furnace front whereby air may pass from said air heating chamber into the furnace, at bafiiing cone eontracted towards the furnace and fitted in an opening in the furnace front in alignment with said casing, a demountable oil burner .lllii mounted on the air casing and extending through said casing as far as the baffling cone, means for admitting air to said air chamber and means for closing the ash pit opening during oil firing.

2. The improved forced draft furnace front adapted for conversion to oil or coal firing comprising a casing covering the furnace front and having an air heating chamber therein, said casing projecting from one wall of said furnace front and terminating on at least one side short of the other wall so as to leave a passage between its end and the said other wall of said furnace front whereby air may pass from said air heating chamber into the furnace, a cylindrical member carrying a baffling cone contracted towards the furnace and fitted in an opening in the furnace front in alignment with said casing, a demountable oil burner mounted on the air casing and extending through said casing and front as far as the baffling cone, means for admitting air to said air chamber and means for closing the ash pit opening during oil firing.

3. The improved forced draft furnace front adapted for conversion to oil or coal firing comprising a casing covering the furnace front and having an air heating chamber therein, the lower wall of said casing terminating short of the rear wall of the furnace front whereby air may pass from said air heating chamber in the casing and furnace, a baffling cone contracted towards the furnace and fitted in an opening in the furnace front in alignment with said casing, a demountable oil burner mounted on the air casing and extending through said furnace front as far as the baffling cone, means for admitting air to said air chamber and means for closing the ash pit opening during oil firing.

LAUNCELOT EUSTACE. SMITH. CORNELIS ZULVER. HERBER T ALEXANDER THOMPSON. 

